In Europe, houses are heated using warm water so its the same. Also, many heat pumps store heat in a warm water buffer. You can use a heat exchanger to heat wat

In Europe, houses are heated using warm water so its the same. Also, many heat pumps store heat in a warm water buffer. You can use a heat exchanger to heat water with it. The american way of heating the house by blowing hot air around isn't the most efficient as air doesn't transport energy very well.